Core and quarter tomatillos, peel and quarter onions, deseed all peppers, and roughly chop, and peel garlic.
Add all vegetables to a large pot, and add 1-1 1/2 cups of water to prevent scorching until the vegetables sweat down, cover pot, and place over medium heat.
Bring to a simmer, stirring occasionally. As vegetables soften, they will release water, and you should end up with plenty of moisture in your pot to keep vegetables from scorching.
Simmer 8-10 minutes until all vegetables are tender.
Remove from heat and add cilantro.
Blend salsa. You can do this in the pot with an immersion blender, or do it in batches in a food processor or blender, being careful not to buy yourself with the hot liquid.
Place pot back over heat, and stir in remaining ingredients.
Bring back to a simmer for 10-15 minutes until salsa has thickened to your desired thickness.
To can:
Prepare water bath canner with hot water.
Sterilize jars and lids (you can sterilize jars by boiling in the water bath canner for 1-2 minutes. Use a jar lifter to remove and drain jars).
Fill prepared jars with hot salsa, leaving a half inch of headspace.
Wipe rims clean if needed, and screw down lids and rings.
Arrange jars in canner so that they don’t touch, place lid on canner, and bring to a rolling boil.
Process pints or half pints for 15 minutes, and quarts for 20 minutes.
remove from heat, and let cool 20 minutes.
Remove jars, and let rest undisturbed for 24 hours. I usually cover hot jars with a towel until they’ve cooled to the point where cool drafts aren’t a danger to them.
After 24 hours, check for seal, wash jars if needed, and store in a cool place out of direct light.